Theses studies are designed to improve understanding of the relationship between bronchial asthma and exposure to indoor allergens. There are at least 8 million asthmatic patients in the United States and approx. 2 million emergency room (ER) visits for the management of acute asthma/year. Studying ER asthma patients there is a highly significant increased incidence of serum IgE antibodies to allergens derived from dusts mites (Dermatophagoides farinae and D. pteronyssinus), cat dander and cockroaches compared to controls. Purified allergens and monoclonal antibodies have been established for dust mite and cat allergens. The present studies will extend the previous studies and in addition will purify cockroach allergens and develop monoclonal antibodies to them. The next objective will be to develop radioimmunoassays for the major allergens of mites (Der f I, Der p I, Der f II, and Der p II), cats (Fel d I), and cockroaches, using monoclonal antibodies. These two site radioimmunometric assays which already been developed for mite allergens, are sensitive, highly specific, rapid and inexpensive. In addition they can easily be standardized relative to National of International Standards and can give results in absolute units (i.e. ug). The assays will be used to study quantities of these allergens both in dust samples and airborne in patients' houses. They will also be used to monitor the effect of allergen avoidance measures on the quantities of allergens to which patients are exposed. A further objective will be to define the relationship between exposure to these indoor allergens and emergency room visits for acute asthma. This will involve measuring IgE antibodies in sera from the patients and measuring allergens in dust from their houses. Our preliminary results suggest that allergy to indoor allergens is a major risk factor for the development of acute asthma in patients less than 50 years old. However there appear to be regional seasonal and socioeconomic factors which influence the prevalence of IgE antibodies in asthmatic patients. We intend to investigate the extent to which these differences in distribution of IgE antibodies among asthmatic patients reflect differences in the quantities of relevant allergens in their houses. The results suggest that better understanding of and control of the levels of allergens in houses would be a major contribution to the management of this disease.